1. Field of the Invention
This invention relates to a system intended for securing a pre-shaped thin-walled external roofing, supported on a layer of medium-hard insulation, on an underlying carrying roof structure supporting the insulation layer, which system has the form of a strip.
2. Description of the Prior Art
Roof structures using soft and, respectively, hard insulation are previously known.
When soft insulation is used, battens of some kind are provided on the same support (usually sectional sheets), which carries the insulation. These battens are secured on the support and carry the external roofing, which normally consists of sheet metal. The insulation proper, thus, in such a structure has no carrying function.
When hard insulation is used, it is laid on a support (sectional sheets) and thereafter secured on the support by special fastening members. These fastening members comprise a cone-shaped body and a self-tapping screw extending therefrom. Said cone-shaped body co-operates with the hard insulation while the self-tapping screw is caused to engage with the sectional sheet constituting the support. When hard insulation is used, the external roofing material usually is roofing felt, which is fixed with glue on the hard insulation.
The two aforesaid roof structures have certain economic disadvantages. The roof structure with soft insulation comprises special battens for supporting the roofing which, of course, renders the structure more expensive. As regards the roof structure with hard insulation, it is generally known that such insulation is more expensive than soft and medium-hard insulation.